Spark plug



Patented July 8, 1924.

UNITED STATES WILLIAM L. BARRON, OF OKLAHOMA CITY, OKLAHOMA.

' SPARK PLUG.

Application filed April 27, 1923. Serial no. 885,082.

To all whom it may concern:

' Be it known that I, WILLIAM L. BARRON, a citizen of the United States, residing at Oklahoma City, in the county of Okla 6 homa and State of Oklahoma, haveinvented certain new and useful Improvements in Spark Plugs, of which the following is a specification.

This invention relates to a spark plug,

and particularly to a construction embodying an air intake throu h said plug.

In the practical-application of plugs of this character, the means for introducing air therein have not been disposed so as to effectually cool the insulating member and also cool and cleanse the firing points, particularly when such points are arranged for w an intensified spark. Such earlier constructions have involved more or less complicated constructions which are avoided in the type of plug herein presented wherein the number of parts is materially reduced and assembled for ready disconnection and cleansin or repair.

6 present invention seeks to provide an improved construction by which an in sulating sleeve is mounted within the usual supportin shell which carries one electrode, while wit 'n the sleeve an opposite tubular electrode is mounted and rovided with an air intake valve, the disc arge from said tubular electrode being so disposed as to directly impinge upon the firing points in order to introduce oxygen to eifect a hot .and firing electrode in its downward passage directly over the latter which also effects a cleansing action by removing any particles of adhering carbon before the same can become caked or baked upon the firing point of the electrode.

A further object of the invention is to provide an improved form of firing electrodes in which the dischar e from the inner or tubular electrode is directly toward a firing ring supported. by an insulating surface, and a secondary discharge or spark passes from this ring to the firing point of tlie electrode connected to the grounded P u V O ther and further objects and advantages of the invention. will be hereinafter set forth and the novel features thereof defined by the appended claims.

spark and also cool the insulating support In the drawing:

Figure 1 is a perspective of the invention applied to an engine;

Figure 2 is a central vertical section thereof;

Figure 3 is a detail perspective of the connecting clip for the terminal wire; and

Figure 4 is a similar view of the firing ring.

Likenumerals refer to like parts in the several figures of the drawing.

The numeral 10 designates the plu shell which may be of any desired con guration and is provided with the usual threaded portion 11 for engagement with a cooperating aperture in the engine head 12, as usual. Depending from this threaded portion is an electrode 13 which has an upturned or reentrantly bent firing point 14. The body of the shell 10 is formed with a chamber 15 adapted to receive a centrally disposed enlarged body 16 of the insulating sleeve 17.

This body portion is clamped in position by a nut 18 threaded at 19 into the chamber 15. Packings of any desired character may be disposed between the faces of the body portion 16 and those of the shell and nut, as indicated at 20. The insulatin member 17 may be formed of any preferred material, such as porcelain or other vitreous substance, and is formed with a central aperture 21 within which a tubular electrode '22 is disposed, the passage 23 therethrough being 1n direct alignment with the firing point 14 of the electrode 13. The lower end of this tubular electrode is formed with a head 24 which rests against a shoulder 25 of the insulatin sleeve, while the upper end of the electr e is threaded as at 26 to receive a connecting valve chamber 27 which is interiorly threaded at 28 and bears against the base of a chamber 29 in the insulating member.

It will be seen that an adjustment of this valve chamber draws the tubular electrode into position and firmly secures the same while also permittin its convenient removal when desired. lhe upper portion of the valve chamber 27 is provided with a valve seat 30 coo crating with a valve 31 the stem 32 of w ich is extended upward. This stem is enclosed by a cap 33 having a receiving chamber 34 and threaded at 35 upon the upper portion of the valve cham I normally held in closed or seated position by a coiled tension spring 38 bearing against this guide 37 and also the upper end of the valve chamber. The guiding action of the cap insures a direct and positiveseating of the valve and prevents any lateral play of the stem which is extended beyond the cap in order that the valve may be manually depressed when desired. This is of particular importance when the chamber in the cap is filled with a priming fluid and the valve depressed to admit this priming charge into the engine cylinder prior to the starting of the engine. The valve is normally operated by the suction incident to the engine stroke and ifthis riming cham- "ber be filled under such conditions the fluid will be drawn into the cylinder for the preliminary priming action, and subsequently a feed of air passes through the same valve and passage.

For the purpose of connecting the terminal to the plug the cap 33 is provided with a groove 40' extendlng circumferentially thereof and adapted to receive the spring arms 41 of a connector, as shown in Figure 3. This connector is preferably formed from a single piece of wire-or like material and the portion 42 thereof is extended at 1 an angle to the spring arms 41 by means of the bent portions 43 connecting these members. The usual conductingwire is connected to the portion 42 of the spring clip in any desired manner.

In order to provide the most efiicient form of intensifying action at the spark gap, an improved construction of these parts has been provided and this embodies a firing ring 44 seated in a recess 45 within the insu-- lating sleeve which isextended below the plug body and is exposed to the action of the charge within the cylinder. This ex'- tended portion is normally cooled by the passage of air through the inner electrode and the head 24 of this electrode is spaced from the firing ring 44 to form a preliminary spark gap at that point, while the firing point 14 of the electrode 13 is disposed within sparking distance of the firing ring 44 so as to secure the secondary or intensified spark between the ring and is not necessarily confined to a circular structure, as it may be of any desired form to eflect the proposed action, but is herein shown as being formed of spring material with a gap -46 by which it may be compressed and expanded into the seat 45 where it 1s firmly held by its expansive tension.

In the operation of the invention the suction stroke of the engine piston draws a charge of air through the tubular electrode,

the aperture of which discharges in direct alignment with the firing point which is thus cooled and cleansed from carbon, while the eflect of such impact is to difiuse the air toward the walls of the porcelain insulator which carries the firing ring and these parts are also maintained in cool condition. This body of air also supplies oxygen at the firing point which is particularly effective in securing the intensified spark contemplated by this invention as the air is applied directly to the first spark gap between the tubular electrode and firing ring. This intensified action is also materially facilitated by the arrangement herein pre sented by which the preliminary and secondary spark gaps are each confined within the extended porcelain insulating portion from the plug. The construction of the air intake also provides a positive simple form of valve which is guided in its action by the cap member and this member is'formed to efitect a priming function of the engine when desired, wh1le the extended stem of the valve permits its manual operation if necessary. The construction and assemblage of parts of this plug permits ready access to the interior members thereof and also to the valve by sim le removal of the cap Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:-

1. In a spark plug, a supporting shell provided with an electrode, an insulating sleeve arranged within said shell and projected beyond the lower end thereof, a tubular electrode within said sleeve, a valve casing mounted upon said electrode at its upper end, a tensioned valve in said casing controlling an air intake to said tubular electrode and having an extended operating stem, and a cap carried by said valve casing to partially enclose and guide the extended end of the valve stem. the point. The term ring as herein used cally disposed stem formed with an enlarged .ing cooperating with said enlarged portion and exposing said extension.

3. In a spark plug, a supportin shell provided with a depending electrode aving a re-entrant firing point, an insulatin slee've supported by sald shell and extende below the lower end thereof to enclose said point, an electrode disposed within said sleeve, and a firing ring carried by the sleeve 1 spaced from the inner electrode. and con- 16 centric to said inilz. sh

4. In a s ar pug a supporting v ell provided with an electrode having a reentrant firing point, an insulating sleeve disposed in said shell and extended beyond 20 the same, a tubular electrode provided with an air inlet, and a firing said sleeve below the tubular electrode and concentric to said firingpoint.

In testimony whereof I aflix niy signa- $5 ture.

5 WILLIAM L. BARRON.

ring mounted in 

